Immunohistochemical analysis of collagen fibrils within the hybrid layer: a FEISEM study

This study evaluated the immunohistochemical labeling pattern of dentin collagen fibrils within hybrid layers created by different bonding systems using high resolution SEM. Four different adhesive materials, including self-etching and total-etching systems, were examined: Prime & Bond NT, OptiBond SOLO Plus, Single Bond and Clearfil Protect Bond. All materials were applied to the dentin of extracted human third molars. After cutting the bonded specimens transversely, an anti-collagen type I antibody was incubated on the surface of the dentin-adhesive interface and gold-conjugated secondary antibody was applied to reveal collagen labeling under high resolution SEM. The hybrid layers showed a significant number of collagen fibrils embedded in the resin matrix. The presence of exposed dentin collagen fibrils, as determined by positive labeling with an anti-type I collagen monoclonal antibody, is considered an indication of the presence of incompletely embedded fibrils and, thus, the quality of dentin matrix hybridization. The hybrid layers produced by total-etching systems showed higher labeling compared to those produced by the self-etching system. Positive collagen labeling was also found along the resin tags produced by total-etching adhesive systems.     

MMP-2 assay within the hybrid layer created by a two-step etch-and-rinse adhesive: biochemical and immunohistochemical analysis

Objective

Degradation of hybrid layers (HLs) within resin-infiltrated dentine results from multiple degradation factors, including collagenolytic activity of specific matrix metalloproteinases (MMPs). Inhibition of host-derived MMPs may, therefore, slow the degradation of HL. The null hypothesis tested is that the presence of MMP-2 is similar regardless of chlorhexidine (CHX) pre-treatment or the use of an adhesive.

Methods

Powdered dentine prepared from extracted human teeth was divided into 4 groups: (G1) mineralised powder (control group); (G2) dentine powder treated with 1% phosphoric acid for 1 min; (G3) 1% phosphoric acid-etched dentine treated with Adper Scotchbond 1 XT (SB1XT; 3M ESPE); (G4) 1% phosphoric acid-etched dentine treated with 0.2% CHX followed by SB1XT. The concentration of detectable pro-MMP-2 and MMP-2 was assayed using a colorimetric assay system (QuantiSir). In addition, the presence of MMP-2 in the HL was assessed in 1 year-aged adhesive-dentine interfaces using an immunohistochemical approach under FEI-SEM/TEM.

Results

In dentine powder treated with 1% phosphoric acid (G2), MMP-2 level decreased compared to controls (G1); the application of SB1XT (G3) resulted in an increase of MMP-2, whilst 0.2% CHX before SB1XT application (G4), reduced MMP-2. The FEI-SEM/TEM analysis revealed MMP-2 distribution within the HL of aged interfaces showing increase MMP-2 patterns in the control group and minor labelling in the CHX-pretreated specimens.

Conclusion

The results of this study support the use of non-toxic MMPs inhibitors, such as CHX, as an appropriate additional step in bonding procedures in order to increase the longevity of the adhesive restorations.     

Orthostatic hypotension and cognitive impairment: a dangerous association?

Many studies have addressed the relation between orthostatic hypotension (OH) and cognitive impairment (CI) in the elderly, in mild cognitive impairment, vascular and neurodegenerative dementias and movement disorders, such as Parkinson’s disease. However, results concerning both the increased coexistence of the two conditions and their causal relationship remain controversial. According to the literature three hypotheses can be formulated on the relation between OH and CI. In neurodegenerative disease, OH and CI may result from a common pathological process which affects areas involved in both cognition and cardiovascular autonomic control. Alternatively, OH may lead to cerebral hypoperfusion which is supposed to play a role in the development of CI. Finally, recent data suggest that CI should probably be considered more a transient symptom of OH than a chronic effect. This study reviews the literature reports on the relationship between OH and CI, and emphasises the need for longitudinal studies designed to investigate this topic.     

Prevention and treatment of type 2 diabetes: current role of lifestyle, natural product, and pharmacological interventions

Common complications of type 2 diabetes (T2D) are eye, kidney and nerve diseases, as well as an increased risk for the development of cardiovascular disease and cancer. The overwhelming influence of these conditions contributes to a decreased quality of life and life span, as well as significant economic consequences. Although obesity once served as a surrogate marker for the risk of T2D, we know now that excess adipose tissue secretes inflammatory cytokines that left unchecked, accelerate the progression to insulin resistance and T2D. In addition, excess alcohol consumption may also increase the risk of T2D. From a therapeutic standpoint, lifestyle interventions such as dietary modification and/or exercise training have been shown to improve glucose homeostasis but may not normalize the disease process unless weight loss is achieved and increased physical activity patterns are established. Furthermore, utilization of natural products may serve as a significant adjunct in the fight against insulin resistance but further research is needed to ascertain their validity. Since it is clear that pharmaceutical therapy plays a significant role in the treatment of insulin resistance, this review will also discuss some of the newly developed pharmaceutical therapies that may work in conjunction with lifestyle interventions, and lessen the burden of behavioral change as the only strategy against the development of T2D.     

Affective temperament and attachment in adulthood in patients with Bipolar Disorder and Cyclothymia

Objective

To examine attachment and affective temperament in patients who have been diagnosed with Bipolar Disorder and to investigate possible differences in both variables among Bipolar I Disorder (BD-I), Bipolar II Disorder (BD-II), and cyclothymic patients.

Methods

Ninety (45 male and 45 female) outpatients with bipolar or cyclothymic disorder between the ages of 18 and 65 years were recruited consecutively between September 2010 and December 2011 at the Bipolar Disorder Unit of the Psychiatry Day Hospital affiliated with the University General Hospital “A. Gemelli” in Rome, Italy. Patients were assessed using the Structured Clinical Interview for DSM-IV, the Hamilton Depression Rating Scale, the Young Mania Rating Scale, the Temperament Evaluation of Memphis, Pisa, and San Diego—auto-questionnaire version, and the Experiences in Close Relationships (ECR) questionnaire applied by trained interviewers.

Results

The 3 groups of patients differed only on the ECR Anxiety scores with BD-I patients having the highest anxiety levels, followed by the BD-II patients, and the patients with cyclothymic disorder reporting the lowest level of anxiety.

Conclusions

This finding suggests that bipolar disorder (type I, type II) and cyclothymic/dysthymic temperament are more strongly associated with insecure attachment style as compared to the general population.